I can never remember which way it is, I think parallel gives high impendance at resonance with high voltage and series gives low impedance at resonance with lower voltage, I'm sure someone will be along soon with the answer.
I have a small collection of vintage valve radios, to test them I have a home bashed transmitter for broadcast am, it has a parallel lc tank circuit which performs 2 jobs, it produces a reasonable clean output from a squarewave input, and the inductor is also the aerial (1 meter square of ally tig welding rods), one end is fed with a radio freq squarewave from a crystal osc and the other end comes from a audio power amp chip.
Local oscillators in tranny radios before they went direct synthesis commonly used parallel oscillators.
I'd reccomend parallel, heres some interesting reading for you :
**broken link removed**